說明：

做sdk開發的時候（sdk不採取任何第三方框架），涉及到下載網路檔案，和載入網路圖片的功能，由於不能用第三方jar包進行，所以只能用基本的HttpURLConnection把檔案作為流來處理，進行下載和載入。

1、HttpURLConnection載入圖片

程式碼：

 /**
     * 載入圖片ImageView
     * @param url 圖片網路地址
     * @return
     */
    public void setImageViewBitMap(ImageView imageView, final String url) {
        this.imageView = imageView;

        new Thread() {
            @Override
            public void run() {
                URL myFileUrl = null;
                Bitmap bitmap = null;
                try {
                    myFileUrl = new URL(url);
                } catch (MalformedURLException e) {
                    e.printStackTrace();
                }
                try {
                    HttpURLConnection conn = (HttpURLConnection) myFileUrl.openConnection();
                    conn.setDoInput(true);
                    conn.connect();
                    InputStream is = conn.getInputStream();
                    bitmap = BitmapFactory.decodeStream(is);
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }

                imageBitmap = bitmap;
                myHandler.sendEmptyMessage(1);
            }
        }.start();
    }
 

2、HttpURLConnection下載檔案

程式碼：

/**
     * 把js,css儲存在本地
     * @param uFile 本地儲存的檔名File路徑
     * @param url 將要下載的js,css檔案
     */ 
    public static void writeUrToStrealm(File uFile, String url) {
        try {
            URL uri = new URL(url);
            URLConnection connection = uri.openConnection();
            InputStream uristream = connection.getInputStream();
            //String cache = connection.getHeaderField("Ddbuild-Cache");
            String contentType = connection.getContentType();
            //textml; charset=utf-8
            String mimeType = "";
            String encoding = "";
            if (contentType != null && !"".equals(contentType)) {
                if (contentType.indexOf(";") != -1) {
                    String[] args = contentType.split(";");
                    mimeType = args[0];
                    String[] args2 = args[1].trim().split("=");
                    if (args.length == 2 && args2[0].trim().toLowerCase().equals("charset")) {
                        encoding = args2[1].trim();
                    } else {

                        encoding = "utf-8";
                    }
                } else {
                    mimeType = contentType;
                    encoding = "utf-8";
                }
            }

            //todo:快取uristream
            FileOutputStream output = new FileOutputStream(uFile);
            int read_len;
            byte[] buffer = new byte[1024];

            SaveDataUtils.writeBlock(output, mimeType);
            SaveDataUtils.writeBlock(output, encoding);
            while ((read_len = uristream.read(buffer)) > 0) {
                output.write(buffer, 0, read_len);
            }
            output.close();
            uristream.close();

        } catch (Exception e) {
            e.printStackTrace();
        }
    }